Economic feasibility and yield of different treatments of potassium management in light textured soil on rabi onion var. Agrifound light red of Western (UP)

A field experiment was carried out to assess the economic feasibility of different nutrient management treatments in light-textured soil on Rabi onion (var. Agrifound Light Red) under the agro-climatic conditions of Western Uttar Pradesh. The study was conducted at the Crop Research Centre, Sardar Vallabhbhai Patel University of Agriculture and Technology, Meerut (U.P.), during the Rabi seasons of 2020–21 and 2021–22. The significantly highest bulb yield ranged from 200.13 to 215.07 q ha⁻¹ in the first year and 297.83 to 322.00 q ha⁻¹ in the second year across various treatments. The maximum bulb yield of 297.83 and 322.00 q ha⁻¹ was recorded in T₁₁ (NP + K₅₀ – 100% basal through Polyhalite), which was statistically at par with T₉ (NPS + K₇₅ – 50% basal + 50% at bulb formation stage) producing 275.46 and 306.00 q ha⁻¹, followed by T₁₀ (NPS + K₇₅ – 25% basal + 37.5% at vegetative + 37.5% at bulb formation stage) with 270.10 and 291.00 q ha⁻¹ during 2020–21 and 2021–22, respectively. The lowest yield (200.13 and 215.07 q ha⁻¹) was obtained from the control treatment (T₁: N₁₀₀ P₅₀ S₄₀) in both years. Yield improvement under T₁₁ was 48%, 35%, 18%, and 12% higher in 2020–21, and 49%, 35%, 25%, and 14% higher in 2021–22, compared to T₁, T₂, T₅, and T₈, respectively. The application of 150% of the recommended potassium dose in two splits, as in T₉ (NPS + K₇₅ – 50% basal + 50% at bulb formation stage), resulted in yield increases of 25%, 14%, 9%, 7%, and 2% in the first year, and 28%, 20%, 19%, 17%, and 5% in the second year, over T₂, T₄, T₅, T₇, and T₁₀, respectively. Similarly, the T₁₀ treatment (NPS + K₇₅ – 25% basal + 37.5% at vegetative + 37.5% at bulb formation stage) achieved higher yields by 34%, 22%, 14%, 7%, and 1.92% during 2020–21 and by 35%, 22%, 17%, 13%, and 3.68% in 2021–22, compared to T₁, T₂, T₃, T₅, and T₈, respectively. Overall, the results clearly indicate that applying the recommended dose of potassium through Polyhalite produces yields comparable to those obtained with 150% potassium application through the conventional fertilizer (MOP), demonstrating its efficiency and economic advantage in Rabi onion cultivation.